I’m not a Python dev so can’t help with debugging the library, but a 401 would likely suggest your Client ID is invalid (eg, you may have copy/pasted some whitespace, or missed characters, etc…). If you log the actual body of the response you’re getting from Twitch it’ll give you the exact reason for the error.
An OAuth token is not currently needed to use the Get Streams endpoint, a Client ID will suffice as long as it is valid. That being said though, from the 30th of April onwards ALL requests to Helix will require both a client ID, and an OAuth token, so you will have no choice but to get an OAuth token, which for requests that don’t require any user scopes you can simply use an App Access Token https://dev.twitch.tv/docs/authentication/getting-tokens-oauth#oauth-client-credentials-flow